Spray counter lightly with non-stick cooking spray. Combine 8 rolls and roll into a 15 inch circle. Cover with plastic wrap and let rest. Cook sausage and drain. Add cream cheese and mozzarella to the hot sausage and mix until cheese is mostly melted. Add Italian seasoning and gently fold in tomatoes, olives and mushrooms. Remove plastic wrap from dough and lift dough into a sprayed 9 inch deep dish pie pan. Dough will cover bottom and sides plus hang over the pan edge slightly.
Combine remaining 4 rolls and roll into a 10-inch circle. Spoon filling over crust in pan. Place 10 inch circle on top of filling. Wipe edge of circle with water and fold excess dough from bottom crust over the top crust and press and pinch together. Whisk egg with 2 teaspoons water and brush over top of crust. Cut a small x in the middle for pie to vent. Sprinkle with Italian seasoning and top with pepperoni. Bake at 350°F 35-45 minutes.